OBJECTIVES: 1. To continue study of modeling in bone disease, with the objective of elaborating signs useful to the diagnostic process. 2. To use signs in computer aided diagnosis. 3. To develop new diagnostic algorithms. 4. To improve the computer system for accomplishing computer assisted diagnosis. 5. To study dysplasias. 6. To maintain and operate the Mid-America Diagnostic Center for the purpose of collecting data base, and providing skilled diagnostic services for unusual problems in radiological diagnosis. BIBLIOGRAPHIC REFERENCES: Lodwick, G.S. and Farrell C.: "Criteria for Radiologic Distinction of Malignant from Benign Tumors of Bone". Weekly Radiology Science Update #34, 1977. Lodwick, G.S., Dahlin, D., Brady, Luther, and Enneking: "A Symposium on the Round Cell Tumors". To be presented at the International Skeletal Society Amsterdam, September, 1977.